The proposed project examines psychiatric nosology and selected risk factors for psychiatric disorders in the context of a representative community-based sample. Psychiatric disorders are examined using three approaches: (a) DIS/DSM-III diagnoses, (b) DIS symptom counts, and (c) symptom profiles generated by grade of membership (GOM) analysis. The GOM analyses are particularly important in that they provide information about the extent to which empirically-based symptom profiles match the diagnostic categories that comprise the nosologic framework of DIS-III. This eclectic approach to psychiatric diagnosis also permits examination of the kinds of mental health problems that are most prevalent in community populations (e.g. symptom syndromes as well as formal diagnoses). Risk factor analyses focus on three areas: (a) the extent to which job characteristics are risk factors for psychiatric disorders, (b) the relationships among life events, social support, social integration, and psychiatric disorders, and (c) the extent to which environmental characteristics of the residential area are risk factors for psychiatric disorders. A variety of statistical modeling techniques will be employed in the risk analyses, including multilevel analysis for examining the impact of enviromental effects. Special attention will be devoted to the interactive, as well as the direct and indirect effects, of the risk factors examined. The proposed analyses will be contribute to our understanding of psychiatric disorders in community populations and the identification of variables that place individuals at increased risk of psychiatric disorders. The data to be used in the proposed project are from the Epidemiologic Catchment Area Program. Most analyses will be used on the Duke ECA sample, but selected analyses will use pooled from all five ECA sites. The proposed analyses included both cross-sectional and longitudinal models. Where possible, length of exposure to the risk factors of interest also will be examined. The proposed project capitalizes upon the richness and breadth of the ECA Project and will examine issues of long- standing interest in psychiatric epidemiology in a creative and methodologically sophisticated manner.